hdu 4681

将c串从a，b串中删去后求最长公子列  直接暴会超时

#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <cstring>
using namespace std;

char a[1010],b[1010],c[1010];
int dp1[1010][1010],dp2[1010][1010];
int aa[1010],bb[1010];
int main()
{
    int t, ca = 1;
    scanf("%d",&t);
    while(t--)
    {
        scanf("%s%s%s",a,b,c);
        memset(dp1, 0, sizeof(dp1));
        memset(dp2, 0 , sizeof(dp2));
        int len1 = strlen(a), len2 = strlen(b), len3 = strlen(c);
        for(int i = 1; i <= len1; i++)
            for(int j = 1; j <= len2; j++)
                if(a[i-1] == b[j-1])
                    dp1[i][j] = dp1[i-1][j-1]+1;
                else
                    dp1[i][j] = max(dp1[i-1][j], dp1[i][j-1]);
        for(int i = len1; i >= 1; i--)
            for(int j = len2; j >= 1; j--)
                if(a[i-1] == b[j-1])
                    dp2[i][j] = dp2[i+1][j+1]+1;
                else
                    dp2[i][j] = max(dp2[i+1][j], dp2[i][j+1]);
        for(int i = 1; i <= len1; i++)
        {
            int u = 0, j;
            for(j = i; j <= len1; j++)
            {
                if(c[u] == a[j-1]) u++;
                if(u == len3) break;
            }
            if(j <= len1) aa[i] = j;
            else aa[i] = 0;
        }
        for(int i = 1; i <= len2; i++)
        {
            int u = 0, j;
            for(j = i; j <= len2; j++)
            {
                if(c[u] == b[j-1]) u++;
                if(u == len3) break;
            }
            if(j <= len2) bb[i] = j;
            else bb[i] = 0;
        }
        int _max = 0;
        for(int i = 1; i <= len1; i++)
            for(int j = 1; j <= len2; j++)
                if(aa[i] && bb[j])
                    _max = max(_max, dp1[i-1][j-1]+dp2[aa[i]+1][bb[j]+1]);
        printf("Case #%d: %d\n",ca++,_max+len3);
    }
    return 0;
}